Effects of the timing of epibrassinolide spraying on yield and nitrogen use efficiency of wide-belt sowing wheat.

In this study, we investigated the effects of epibrassinolide spraying at different growth stages on grain yield and nitrogen use efficiency (NUE), and uptake efficiency (UPE) of wide-belt sowing wheat. The results showed that epibrassinolide spraying enhanced wheat grain yield by increasing the number of kernels per spike and (or) 1000-kernel weight, and improved NUE by promoting aboveground nitrogen accumulation and improving UPE. However, the magnitudes of such enhancements in yield and NUE differed among spraying times. Spraying epibrassinolide at the erecting and filling stages, jointing and filling stages, erecting, jointing, and filling stages, as well as erecting, flowering, and filling stages, produced the greatest increase in the number of kernels per spike and 1000-kernel weight, which led to substantial yield increases (12.8%-14.0%), and the greatest increase in aboveground nitrogen accumulation, which improved UPE by 16.4%-18.8%, and resulted in a significant improvement in NUE. Therefore, spraying epibrassinolide at the erecting and filling stage or jointing and filling stages could achieve high yield and NUE in wide-belt sowing wheat.

[Interactive effects of irrigation regime and planting density on grain yield and water use efficiency in winter wheat]. / 灌水量与密度互作对冬小麦籽粒产量和水分利用效率的影响.

To get an optimal irrigation regime and planting density for simultaneous improvement of grain yield (GY) and water use efficiency (WUE) in winter wheat, we examined the responses of 'Tainong 18' (with bigger ears) and 'Shannong 22' (with medium-sized ears) under four irrigation regimes, including 0, 45, 60, and 75 mm. Those two cultivars were planted at four densities: Tainong 18 at 135×104, 270×104, 405×104, and 540×104 plants·hm-2 and Shannong 22 at 90×104, 180×104, 270×104, and 360×104 plants·hm-2. The interactive effects of irrigation regimes and plant densities on GY, water consumption characteristics, and WUE were investigated. The results showed that GY, evapotranspiration, soil water consumption, and WUE were significantly affected by irrigation regime, plant density, and their interaction. The optimal irrigation regime was 45 mm for both cultivars, while the optimal plant density was 405×104 plants·hm-2 for Tainong 18 and 270×104 plants·hm-2 for Shannong 22, as indicated by the highest GY, the lowest ratio of soil evaporation to evapotranspiration after jointing, and higher WUE and the ratio of soil water consumption below 1 m to total soil water consumption. The rational combination of plant density and irrigation could reduce unnecessary water consumption and improve WUE.

[Correlation between nitrogen fruiting efficiency and nitrogen utilization and remobilization in winter wheat at different sowing dates]. / ä¸åŒæ’­æœŸå†¬å°éº¦æ°®ç´ å‡ºç±½æ•ˆçŽ‡ä¸Žæ°®ç´ åˆ©ç”¨åŠè½¬è¿çš„ç›¸å ³æ€§.

To understand the correlation between nitrogen fruiting efficiency and nitrogen utilization and remobilization in winter wheat, the differences and mutual relationships of nitrogen fruiting efficiency, nitrogen utilization and remobilization of winter wheat at different sowing dates (S1:24 September, S2:1 October, S3:8 October, S4:15 October and S5:22 October) were analyzed in two growing seasons from 2014 to 2016. The results showed that there was no significant difference in grain yield and grain number per unit area among different sowing dates. Delayed sowing date decreased nitrogen accumulation in both shoots and spikes, and then reduced nitrogen uptake efficiency and increased nitrogen utilization efficiency and nitrogen fruiting efficiency. Nitrogen fruiting efficiency was positively correlated with nitrogen utilization efficiency, negatively correlated with nitrogen uptake efficiency, but not significantly correlated with nitrogen use efficiency. Nitrogen nutrition index tended to be optimum with delayed sowing dates, showed synchronicity with the improvement of nitrogen fruiting efficiency. Pre-anthesis nitrogen remobilization amount in vegetative organs and post-anthesis nitrogen accumulation amount significantly decreased with postpone of sowing dates, but pre-anthesis nitrogen remobilization efficiency remarkably rise. There was a positive correlation between nitrogen fruiting efficiency and nitrogen remobilization efficiency, indicating that the improvement in nitrogen remobilization efficiency facilitated the increment in nitrogen frui-ting efficiency. Taken together, properly delayed sowing date reduced nitrogen uptake, but increased nitrogen utilization efficiency and nitrogen fruiting efficiency and improved nitrogen supply status, which provided a theoretical basis for the implementation of reducing input and improving nitrogen utilization efficiency in wheat production in this region.

[Effects of wide-range planting on the yield and nitrogen use efficiency of winter wheat cultivar Tainong 18.] / å®½å¹ æ’­ç§å¯¹å†¬å°éº¦'泰农18'äº§é‡å’Œæ°®ç´ åˆ©ç”¨çŽ‡çš„å½±å“.

The effects of wide-range planting (WR) versus drilling-planting (DP) on grain yield, nitrogen use efficiency (NUE), and nitrogen uptake efficiency (UPE) were investigated using winter wheat cultivar Tainong 18 at experimental fields in Tai'an and Yanzhou during the growing seasons of 2015 and 2016. The results showed that planting pattern, experimental field location, and their interaction significantly affected the grain yield, NUE, and related indices of cultivar Tainong 18. Compared to DP, the WR pattern significantly increased grain yield by 22.5% and 15.4% at Tai'an and Yanzhou, respectively, by raising the number of spikes per unit area at maturity (originating from the greater numbers of tillers per plant and per unit area) and the number of spikes per plant. Compared to DP, the WR pattern significantly increased UPE by 27.7% and 17.5% at Tai'an and Yanzhou, respectively. NUE with the WR pattern at Tai'an and Yanzhou was also increased, respectively, by 22.5% and 15.4% by enhancing nitrogen accumulation and increasing the UPE. A stonger positive effect on yield was observed at Tai'an than at Yanzhou. Thus, the popularization and application of a WR pattern would synergistically improve grain yields and NUE in winter wheat.

Harvesting more grain zinc of wheat for human health.

Increasing grain zinc (Zn) concentration of cereals for minimizing Zn malnutrition in two billion people represents an important global humanitarian challenge. Grain Zn in field-grown wheat at the global scale ranges from 20.4 to 30.5 mg kg-1, showing a solid gap to the biofortification target for human health (40 mg kg-1). Through a group of field experiments, we found that the low grain Zn was not closely linked to historical replacements of varieties during the Green Revolution, but greatly aggravated by phosphorus (P) overuse or insufficient nitrogen (N) application. We also conducted a total of 320-pair plots field experiments and found an average increase of 10.5 mg kg-1 by foliar Zn application. We conclude that an integrated strategy, including not only Zn-responsive genotypes, but of a similar importance, Zn application and field N and P management, are required to harvest more grain Zn and meanwhile ensure better yield in wheat-dominant areas.

[Stability of a winter wheat population with high yield and high resource use efficiency]. / å†¬å°éº¦é«˜äº§é«˜æ•ˆç¾¤ä½“çš„å¹´é™ é—´ç¨³äº§æ€§èƒ½.

Using the winter wheat cultivar Tainong 18 as the experimental material, we analyzed yield stability from 2012 to 2016 under three different treatments: T1(following typical local field management practices), T2(high-yield: high nitrogen and water were supplied to foster high grain yield), and T3(high-yield, high-efficiency: optimized field management including increasing plant density, reducing nitrogen input and delaying of the sowing date). Yield related phenotypic traits, including the number of ears on the main stem and tillers, leaf area index (LAI), photosynthetically active radiation (PAR) interception, dry matter accumulation and distribution, as well as grain yield, were analyzed over four seasons to determine their relationships with annual radiation, accumulated temperature and precipitation. We then determined grain yield stability for each of the three treatments. The amount and distribution of radiation, accumulated temperature, and precipitation varied greatly within each season. The ears on the main stem represented 38.9%, 58.7%, and 66.9% of the total ears, respectively, for wheat grown in the T1, T2 and T3 treatments, indicating that T1 ears originated mainly from the tillers, T2 ears from both the main stem and the tillers, and T3 ears from the main stem. The T2 and T1 treatments produced the highest and lowest amount of dry matter and grain yield, respectively. Although having relatively lower dry matter accumulation at maturity compared with T2, T3 led to higher grain yield due to high LAI, high PAR interception and utilization, high net canopy photosynthetic rate from booting (especially from 14 days after anthesis) to maturity and a higher harvest index. Among the three treatments, T3 resulted in the lowest annual range, standard deviation, and coefficient of variation for LAI, PAR interception, and dry matter accumulation. Thus, grain yield was most stable in wheat grown in the T3 treatment mainly due to stability in biological production during all four seasons.

[Effects of plant density and nitrogen level on nitrogen uptake and utilization of winter wheat].

A two-year (2011-2012 and 2012-2013) field experiment was conducted on one winter wheat cultivar supplied with two levels, of nitrogen (180 and 240 kg N · hm(-2)) under three plant densities (135 x 10(4), 270 x 10(4), and 405 x 10(4) plants · hm(-2)) . The 15N-labeled urea was injected into 20, 60 and 100 cm soil depths, respectively, aiming to investigate the effect of nitrogen and plant density and their interaction on the N uptake, utilization and nitrate nitrogen contents at different soil depths. The results showed that increasing the plant density from 135 x 10(4) to 405 x 10(4) plants · hm(-2) significantly increased the 15N uptake at depths of 20, 60 and 100 cm averagely by 1.86, 2.28 and 2.51 kg · hm(-2), respectively, and increased the above ground N uptake (AGN) , N uptake efficiency (UPE) averagely by 12.6% and 12.6%, respectively, but decreased the N utilization efficiency (UTE) by 5.4%. Compared to the N input of 240 kg N · hm(-2) the 180 kg N · hm(-2) significantly reduced the 15N uptake at depths of 20 and 60 cm averagely by 4. 11 and 1.21 kg · hm(-2), respectively, and significantly increased the 15N uptake at depths of 100 cm averagely by 1.02 kg · hm(-2). Reducing the N input decreased the AGN averagely by 13.5%, but significantly increased the UPE and UTE by 9.4% and 12.2%, respectively. Equivalent grain yield was observed among N input of 180 kg N · hm(-2) with plant density of 405 x 10(4) plants · hm(-2) and N input of 240 kg N · hm(-2) with plant densities of 270 x 10(4) and 405 x 10(4) plants · hm(-2). Increasing the plant density or reducing the N input could encourage the N uptake at deep soil profile and increased UPE and UTE by 13.4% and 11.9%, respectively. Meanwhile, both the nitrate nitrogen contents in 0-200 cm soil layers at maturity and the ratio of the nitrate nitrogen in 100-200 cm soil layers to that in -200 cm were significantly decreased. Therefore, properly decreasing the N input with increasing the plant density of winter wheat was efficient in absorbing N at deep soil, synergistically obtaining high grain yield, UPE and UTE, and reducing the pollution of residual soil nitrate.

[Effects of cultivation patterns on the radiation use and grain yield of winter wheat].

Taking winter wheat cultivar 'Tainong 18' as test material, this paper set three treatments, local farmer's traditional cultivation pattern (FP), super high yield pattern (SH) and high yield high efficiency pattern ( HH) to investigate the effects of cultivation patterns on the intercepted photosynthetically active radiation (IPAR), PAR use efficiency (RUE), dry matter (DM) accumulation, harvest index (HI), grain yield and fertilizers' partial factor productivity (PFP) in 2012-2013. The results showed that IPAR, RUE and DM accumulation of the total growth stage and grain yield under SH pattern were significantly higher than those under FP pattern. IPAR of the total growth stage under HH pattern was lower than that under FP pattern, but RUE, DM accumulation and HI were significantly higher than that under FP pattern, so grain yield was higher than that under FP pattern. The grain yields under HH pattern were respectively decreased by 3.8% and 2.8% under high and low fertility levels compared that under SH pattern, while the PFP of N, P and K under HH pattern were averagely 26.4%, 68.5% and 92.6% higher than those under SH pattern, respectively. In conclusion, HH pattern, with the characteristics of 'reducing fertilizer', 'increasing planting density' and 'delaying sowing date', was the recommended cultivation pattern under the condition similar to this experiment balancing the grain yield, radiation use and fertilizer use.

[Effects of irrigation scheme on the grain glutenin macropolymer's size distribution and the grain quality of winter wheat with strong gluten].

Taking two winter wheat (Triticum aestivum L.) cultivars (Gaocheng 8901 and Jimai 20) with high quality strong gluten as test materials, a 2-year field experiment was conducted to study the grain glutenin macropolymer (GMP)'s content and size distribution, grain quality, and grain yield under effects of different irrigation schemes. The schemes included no irrigation in whole growth period (W0), irrigation once at jointing stage (W1), irrigation two times at wintering and jointing stages (W2), respectively, and irrigation three times at wintering, jointing, and filling stages (W3), respectively, with the irrigation amount in each time being 675 m3 x hm(-2). Among the test irrigation schemes, W2 had the best effects on the dough development time, dough stability time, loaf volume, grain yield, GMP content, weighted average surface area of particle D(3,2), weighted average volume of particle D(4,3), and volume percent and surface area percent of particle size >100 microm of the two cultivars. The dough development time, dough stability time, and loaf volume were negatively correlated with the volume percent of GMP particle size <10 microm and 10-100 microm, while positively correlated with the volume percent of GMP particle size >100 microm, D(3,2), and D(4,3). It was suggested that both water deficit and water excess had detrimental effects on the grain yield and grain quality, and irrigation level could affect the wheat grain quality through altering GMP particle size distribution.

[Effects of planting density on root spatiotemporal distribution and plant nitrogen use efficiency of winter wheat].

Taking winter wheat cultivars Tainong 18 (TN18) and Shannong 15 (SN15) as test materials, a field experiment was conducted to study the effects of planting density (135 x 10(4), 270 x 10(4), and 405 x 10(4) plants x hm(-2) for TN18; 172.5 x 10(4), 345 x 10(4), and 517.5 x 10(4) plants x hm(-2) for SN15) on the root spatiotemporal distribution and plant nitrogen use efficiency of the varieties. For TN18, its root length density, total root absorbing area, and active root absorbing area increased with increasing planting density, and peaked at planting density 405 x 10(4) plants x hm(-2) during the whole growth period. For SN15, its root length density, total root absorbing area, and active root absorbing area achieved the highest values at planting density 345 x 10(4) plants x hm(-2) at booting and late grain-filling stages. The grain yield, nitrogen uptake efficiency, nitrogen partial factor productivity, and nitrogen use efficiency of TN18 were the highest at planting density 405 x 10(4) plants x hm(-2), and those of SN were the highest at planting density 345 x 10(4) plants x hm(-2) but had less differences between the densities 345 x 10(4) and 517.5 x 10(4) plants x hm(-2). The inorganic nitrogen accumulation in different soil layers decreased with increasing planting density at maturity stage. Taking grain yield and nitrogen use efficiency into consideration, the appropriate planting density of TN18 and SN15 would be 405 x 10(4) and 345 x 10(4) plants x hm(-2), respectively.

[Effects of different irrigation modes on winter wheat grain yield and water- and nitrogen use efficiency].

Taking the widely planted winter wheat cultivar Tainong 18 as test material, a field experiment was conducted to study the effects of different irrigation modes on the winter wheat grain yield and water- and nitrogen use efficiency in drier year (2009-2010) in Tai' an City of Shandong Province, China. Five treatments were installed, i. e., irrigation before sowing (CK), irrigation before sowing and at jointing stage (W1), irrigation before sowing and at jointing stages and at over-wintering stage with alternative irrigation at milking stage (W2), irrigation before sowing and at jointing and flowering stages (optimized traditional irrigation mode, W3), and irrigation before sowing and at over-wintering, jointing, and milking stages (traditional irrigation mode, W4). The irrigation amount was 600 m3 hm(-2) one time. Under the condition of 119.7 mm precipitation in the winter wheat growth season, no significant difference was observed in the grain yield between treatments W2 and W4, but the water use efficiency was significantly higher in W2 than in W4. Comparing with treatment W3, treatments W2 and W4 had obviously higher grain yield, but the water use efficiency had no significant difference. The partial factor productivity from N fertilization was the highest in W2 and W4, and the NO3(-)-N accumulation amount in 0-100 cm soil layer at harvest was significantly higher in W2 than in W3 and W4, suggesting that W2 could reduce NO3(-)-N leaching loss. Under the conditions of our experiment, irrigation before sowing and jointing stages and at over-wintering stage with alternative irrigation at milking stage was the optimal irrigation mode in considering both the grain yield and the water- and nitrogen use efficiency.

Effects of different water availability at post-anthesis stage on grain nutrition and quality in strong-gluten winter wheat.

Wheat (Triticum aestivum L.) is one of the most important agricultural crops worldwide. However, water is the most important limiting factor for wheat production. This study was initiated to test water stress environmental effects on grain quality and nutritional value of wheat by using single different water conditions at post-anthesis stage. Further analyses were conducted to examine variations in concentrations and compositions of the bioactive compounds and nutritions in strong-gluten winter wheat subjected to different levels of water deficit during grain filling. For the experiment on the response to different soil water conditions during post-anthesis stage, effects of soil water environment on protein content and composition in the grains were significant. Soil water conditions in this study greatly affected mineral contents in the grains of winter wheat, particularly with regard to the major minerals (P, K, Ca and Mg). Water deficit during grain filling can result in a decrease in lipid contents in wheat grains, which agrees well with experimental findings elsewhere. Concomitantly, a mild water deficit during grain filling would be beneficial to the grain filling and starch compositions, significantly improved bread-making quality. Therefore, it was concluded that good management of wheat field water at post-anthesis stage was helpful to improving grain quality and nutritions relevant to processing and human nutrition.

[Effects of post-anthesis irrigation frequency on the grain quality of strong gluten winter wheat cultivars].

In order to investigate the effects of post-anthesis irrigation frequency on the grain quality of strong gluten winter wheat, two cultivars Jimai 20 and Gaocheng 8901 were subjected to a series of irrigation frequencies under rainfall proof conditions, with their grain yield and grain quality (farinograph parameters and loaf volume) and protein composition evaluated. The results indicated that with increasing irrigation frequency, the grain yield of the two cultivars, their wheat flour dough development time, dough stability time, and loaf volume were noted to be increased first but decreased then. The grain yield and quality of Gaocheng 8901 were the highest when irrigated once after anthesis, while those of Jimai 20 were the best when irrigated twice after anthesis, respectively. The contents of monomeric protein, soluble glutenin, insoluble glutenin, total glutenin, flour protein, and wet gluten in the grains displayed the similar trends. Stepwise regression analysis showed that under the test post-anthesis irrigation frequencies, the key factor affecting dough stability time was insoluble glutenin content, and loaf volume was significantly correlated with total glutenin content. It was suggested that to maintain the quality stability of high grade strong gluten winter wheat, irrigation management should take the improvement of grain protein composition, and glutenin in particular, as the target.